There are three types of tax that you will be responsible for when you start your eBay business. They are 1) sales and use tax, 2) payroll tax and 3) income tax.

Sales and use tax - Just about every state, and many cities and other local authorities, imposes a sales tax on items sold. Each state has different rules, so it's important to find out the rules in your state and city. As a seller, you are responsible for collecting and remitting the proper sales tax to the state you live in. You are also responsible for preparing and submitting a report detailing the amount of your sales and the sales tax collected.

You may also be subject to use taxes. This is taxes on goods you purchased out of state that you did not pay sales taxes on. The use tax generally applies to items purchased out of state which would have been subject to sales tax if the purchase transaction had taken place in state. The use tax came about from the concern that purchasers could avoid paying a state's sales tax by making their purchases outside the state.

Payroll tax - The second type of tax that you are responsible for as an eBay seller is payroll tax. If you hire employees to help you with your eBay business, you are required to withhold federal income taxes, Social Security and Medicare taxes, and state income taxes. These taxes must be submitted to the proper tax authorities on a periodic basis (usually quarterly). In addition you must pay unemployment insurance and workers' compensation on all employees.

If you operate your business as an S or C Corporation, you will need to setup payroll for yourself, and remit payroll taxes on your own salary. If you operate as a Sole Proprietorship, you pay self employment tax instead of payroll tax.

Income tax - The final type of tax is the income tax. No matter how your business is structured, you will be required to pay income tax on the business' net profit.

Sole Proprietors pay income tax on their personal income tax return (Form 1040). Your business profit is calculated using Schedule C – Profit or Loss From Business, and your profit is added to your other income to determine your tax liability.

S Corporations file Form 1120S to report the business profit or loss. A Schedule K-1 is then prepared, which shows each shareholder's share of the net profit or loss that needs to be declared on their personal tax return.

C Corporations file Form 1120 to both report the business net profit and to calculate the resulting income tax.

Depending on the state you do business in, you may also be subject to state income taxes on your business profits. The state level taxes are often referred to as franchise taxes.